well last saturday me and my mate put my new amp in goes hard makes my 7 x 10's sound like i got subs in the back already. now wednesday night i bought a 15 inch sub and installed it and everything connected it to the amp. but when i plug the rca's in and everytime i turn the music a buzzing sound is coming from my 7 x 10's does anyone know how to fix it. and plus i have sorta no idea how to tune the amp to the sub can anyone help with this as well

Sounds like you have a ground loop there kypr30..... can be very very hard to track down.

FIRST: Make sure that your earths (grounds) are clean, try and sand some of the paint away from where you connected them to the chassis.

SECOND: Also add an earthing strap EQUAL to your power wire from the chassis back to the battery.....or from many points back to the battery. see this post: http://www.aussiemagna.com/forums/showpost.php?p=276722&postcount=15 (and read the whole thread)
You can see he has made several earths back to the battery in an effort to get rid of voltage drop (dimming headlights on the beat) and any interference.

These may not fix the problem, but are good practice in audio anyway. You may see the problem gone after this.

NEXT: Make sure your RCA's are as far away from the power wire as possible. If they have to cross over, make sure they do it at 90degree angles. If both power wire and RCAs run down the same side of the car, put the RCAs down the other side.

If still no joy

THEN: make sure the amp itself is not earthed to ground (like a metal screw touching the metal case of the amp been screwed into the chassis or metal of the car). Get some MDF, screw that to the car, then screw the amp down to that.

That should get rid of most buzzing. If it is still there, then you need to look at your RCA cables (replace) or possibly look at filters (does the noise increase with engine revs?)

Hope that gives you a start mate...

I think upgrading the ground at the battery would be last on ur list.

Simple things like headunit ground, amp ground and rca placement should solve most problems and cost least money

i think everyone missed the point.
your problem is called: Cancelling out frequencies

what happened is your sub is playing the same tones as your 7*10, hence the buzzing.
in a good SQ car you wont find bass drivers at the back.

my advise is to get rid of your 7*10 or to add a x-over that filters any requency below 150 hz. (hence rendering it useless)

to tune your amp: turn the gains to MAX and turn your volume knob to max - this will cause it to distort, then adjust (turn back) your gains until you hear no more distortion.

if your sub has a x-over set it at 150hz for the time being, over time you will have to decrease it to around 80hz.

make sure that you did wire your sub properly ( -ve /-ve, +ve/+ve)

some subs have a switch that invert the paths ( this is used only in cases where the subs are upside down - firing "inwards" instead or "outwards"

also check that your box is sealed well.

Buzzing sounds to me to be the cause of noise entering the system more than cancellation. Cancellation doesnt add noise. It cancels it out. Causing reduced output.

And sometimes it is beneficial to run a sub out of phase, it disguises it's location. (Not always though)

But I agree with not using rear speakers or crossing them at 100-300 hz to ensure there is no cancellation and distortion of the rears if you are going to use them.

lol I got into a car last night with only rears playing and it was just wrong. I slapped myself to stop myself fading it forward.

I still prefer my rears they are the best model of all... It's called unplugged :)

When ur system is staging right you will still hear sounds behind you.

Peace

Tim

SQ is overated
There is a Difference between Sound Quality and an SQ system..
What sounds good to one sounds bad to an SQ purist..
The Night Club system is where its at.. Front Rears and Sub..

If he has 7x 10's and a Sub big deal.. I run 6.5inch Splits, 6x9's and a 12 inch ported and can put most " Sq Systems" to shame..


Buzzing is Noise, not frequency Cancellation..
More to the point Buzzing is associated with Resonant Frequency..

Ground loop problem is more the suspect.. a Ground Loop Isolator on the RCA line should reduce the Buzzing..
You say you turn the music up, is the Buzzing there even when the car engine is off ??
You may find you have a panel that is resonanating..


To SQ fans it is all about Imaging and Sound Stage.. as for the concert Scenario.. Its not much good going to a concert and having all your stage upfront if you got Back row seats.. You won't hear anything.. Go to a Night Club and the sound surrounds and pumps hard no matter where you are..

If you have Rears use them..

Sounds like someone who hasnt heard a good system :p

If you want a true nightclub feel, run all ur speakers in mono and drown them out with excessive bass.

I have no problems with people liking this music, I goto clubs and enjoy it after a few drinks

But if you are looking to reproduce the music the way it was intended to be heard, an SQ system is the go.

With decent front splits and enough power behind them they will sh!t over any headunit playing four speakers with <20 w rms a side. In any seating position.

Not just in terms of SQ (Staging, accuracy etc) But in terms of volume. Bass response and recreating that 'nightclub feel'

My system surrounds me totally using only fronts and a sub. Ignoring the way the brain processes noises coming from the rear, reflections alone will cause sound to appear from behind you.

Anyone who has heard a system that comes alive using only two channels will appreciate this. Give it a shot and see if I'm wrong. I used to run 6x9's in the back, 4" in the front and a 10" subs in my old wagon. I would fade it right to the back and used to LOVE it. Now I hate it to the point of me not wanting to travel in cars with bad systems for extended periods of time. I'd prefer silence.

Peace

Tim

I like sound all round, however there is something to be said for the two front speakers banging hard plus sub. Yes, you do hear stuff behind you too....

What I like is the ronts going hard, rear 6x9's filling at like 50% volume of the front..... and subs all the way up :badgrin:

Hey pop up a pic of ur upgraded grounds Mitsi. Where did u mount em? Or just replace the factory ones into the same holes

A bit of rear fill is cool especially with passengers, I used to go maybe 10%. Good to run them in mono if ur after SQ. If your rear stages it tends to affect the front staging, If there is no distinguishable staging at the back the fronts will still have good stereo imaging.

And make sure there is no blending with the sub and the rears as they will cause issues with cancellation. Highpass around 150 hz if possible.

hahaha, go the 15s!! woo :fruitcake

I'd like to see your 'upgraded' grounds too MitsiMonsta. I wanna replace the current ones, and I might as well find some other interesting looking points while I'm lurking in the engine bay.

Hey pop up a pic of ur upgraded grounds Mitsi. Where did u mount em? Or just replace the factory ones into the same holes

I'd like to see your 'upgraded' grounds too MitsiMonsta. I wanna replace the current ones, and I might as well find some other interesting looking points while I'm lurking in the engine bay.
Okay, okay, will get a pic or two and post them. Nothing at all special. Just an extar 4g


A bit of rear fill is cool especially with passengers, I used to go maybe 10%. Good to run them in mono if ur after SQ. If your rear stages it tends to affect the front staging, If there is no distinguishable staging at the back the fronts will still have good stereo imaging.
Never thought about the staging... it's a good point. I just like a bit of sound coming from the rear.
Before I re-wired my car with the XM444 doing both the fronts and the rears (and had no 6x9's going at all), I found that I was hearing stuff around me.... so much so that my head would snap areound to see where it was coming from! And that was only from coaxials in the front!


And make sure there is no blending with the sub and the rears as they will cause issues with cancellation. Highpass around 150 hz if possible.
The amp only has a LPF (fixed 80hz) on the 'rear' channels, and a HPF (fixed 80hz) on the 'front' channels, so the 6x9's are running full frequency at the moment. The fronts are HPF'd at 80Hz.

SQ freaks will tell you to High pass the 6x9's I say let them thump to accompany the sub..
You will experience a Nice Mid range hump, If your deck has sub out, then just fade them a tad to the front..

Set up the system the way you think it should be run... You are the one who owns it and has to listen to it...

SQ freaks will tell you to High pass the 6x9's I say let them thump to accompany the sub..
You will experience a Nice Mid range hump, If your deck has sub out, then just fade them a tad to the front..

Set up the system the way you think it should be run... You are the one who owns it and has to listen to it...
argh no!
6x9's are fine running full range off an OEM headunit they can handle 10 w rms. BUt through any decent amp, (or even a decent headunit) is a different kettle of fish.

There is a big difference between mid range and sub range. Mid range is what most people with 6x9's beleive is sub frequencies, (Most beats that hit you in the chest) These are 80 - 250 hz frequencies. Below 80 hz is sub frequencies (Rnb, drum n bass etc)

Seriously, 6x9's are not a sub. They cannot play frequencies below their resonant frequency. Try it! Pump them hard by themselves with a full range then pump them hard by themselves with 100 hz hp. (I say 100 hz as the 100 hz is not a wall, at 100 hz with a shallow 6 db/oct since the slope is so shallow the crossover will gradually attenuate frequencies below 100 hz. By the time it gets down to sub frequencies they should be almost no noticeable 80 hz frequencies coming fro the woofer.
You can go much louder highpassed. Now try highpassing with the sub, the sub should easily take care of the sub frequencies 20 - 80 hz. Just the same that i wouldnt want you playing mid frequencies through a tweeter.

If you feed a signal that it cant play, especially in a boot with no natural dampening the cone will bottom out.

It sounds like ass!

If you have a sub it is not a good idea to blend the power of a sub against a flimsy cone of a 6x9 when they are using the same enclosure (the boot)
The 6x9 cone will be excurting with the subs pressure. As long as the frequencies are not near the sub frequncies, this distortion will not be evident.

Feel free to do it the way you think is best, just realise there are better ways. I find many people beleive each speaker should be going as hard as it can, and every amp should be working at 90% just before clipping.

I went through this stage, eventually you realise that you want to play audio for urself and not to parade around to every other car on the road. Distortion is more evident to listeners from a distance, at such short range in a car, ur brain is overloaded and doesnt process everything. Even if you arent noticing the distortion chances are cars next to you are laughing.

Peace

Tim

or you could put the 6x9's in their own enclosure (sealed).

Make fibreglass boxes and tack them underneath the parcel shelf....

to tune your amp: turn the gains to MAX and turn your volume knob to max - this will cause it to distort, then adjust (turn back) your gains until you hear no more distortion.

I hope that was a joke Mercury :nuts:

to tune your amp: turn the gains to MAX and turn your volume knob to max - this will cause it to distort, then adjust (turn back) your gains until you hear no more distortion.

I hope that was a joke Mercury :nuts:
lol Good find Mr C

Everyone should take note that you should turn your Gains to minimum and ur headunit to the highest point before it distorts. Then slowly raise the gains until the speakers start to distort, and dial it back a bit

one of these weekends tim, i'm gonna come over to your joint with a case of beer, and get you to install and tune all my sh1t properly..... that's once i get all of the parts to work properly first!!

lol Good find Mr C

Everyone should take note that you should turn your Gains to minimum and ur headunit to the highest point before it distorts. Then slowly raise the gains until the speakers start to distort, and dial it back a bit

ohh really? so was that why my stuff was smoking? :bowrofl:

yeh, then u play with the other knobs...u can play with knobs all day until u get it right. just remember to wear protection. ;)

one of these weekends tim, i'm gonna come over to your joint with a case of beer, and get you to install and tune all my sh1t properly..... that's once i get all of the parts to work properly first!!
Yerr I should set up shop here...

When Im back at uni next semester I should be able to find a bit more time. Beer makes install fun... *Pokes screwdriver through speaker surround... :cool:

Peace

Tim

Yerr I should set up shop here...


You'll so get bored of it, if your doing it everyday